Group III-V nitride semiconductors have been spotlighted as a core material of light emitting devices, such as light emitting diodes (LEDs) or laser diodes (LDs), due to physical and chemical characteristics thereof. A Group III-V nitride semiconductor is generally formed of a semiconductor material having a formula of IxAlyGa1−x−yN (0≦x≦1, 0≦y≦1, 0≦x+y≦1).
A light emitting diode (LED) is a semiconductor device which converts electricity into infrared or visible light using characteristics of compound semiconductors to exchange signals, and is used as a light source.
LEDs or LDs using such a nitride semiconductor material are widely used for light emitting devices for obtaining light and are used as light sources of various types of products such as a keypad light emitting unit of a mobile phone, a display apparatus, an electronic display board and a lighting apparatus.